Continuous fiber 3D printing (a.k.a., CF3D™) involves the use of continuous fibers embedded within material discharging from a moveable print head. A matrix is supplied to the print head and discharged (e.g., extruded and/or pultruded) along with one or more continuous fibers also passing through the same head at the same time. The matrix can be a traditional thermoplastic, a powdered metal, a liquid resin (e.g., a UV curable and/or two-part resin), or a combination of any of these and other known matrixes. Upon exiting the print head, a cure enhancer (e.g., a UV light, an ultrasonic emitter, a heat source, a catalyst supply, etc.) is activated to initiate and/or complete curing of the matrix. This curing occurs almost immediately, allowing for unsupported structures to be fabricated in free space. And when fibers, particularly continuous fibers, are embedded within the structure, a strength of the structure may be multiplied beyond the matrix-dependent strength. An example of this technology is disclosed in U.S. Pat. No. 9,511,543 that issued to Tyler on Dec. 6, 2016 (“the '543 patent”).
Although continuous fiber 3D printing provides for increased strength, compared to manufacturing processes that do not utilize continuous fiber reinforcement, inter-layer strength can be too low for some applications. Specifically, when new material is discharged over the top of a layer of existing and already-cured material, the bond between the layers of material may be low due to a lack of fibers extending between the layers. And in some applications, this reduced inter-layer strength may be problematic.
The disclosed system and method are directed to addressing one or more of the problems set forth above and/or other problems of the prior art.